# Appendix 10.13

Table 10-16

Reference 6: Tables 18 and 19 on pages 22 and 23 and Table 29 on page 40 of "BART Application Analysis (AP-6041) for Dave Johns ton Power Plant", May 28, 2009DEPARTMENT OF ENVIRONMENTAL QUALITY AIR QUALITY DIVISION

BART Application Analysis

AP-6041

May 28, 2009

NAME OF FIRM: PacifiCorp

NAME OF FACILITY: Dave Johnston Plant

FACILITY LOCATION: Sections 7 and 18, T33N, R74W

UTM Zone: 13 Easting: 436,592 m, Northing: 4,742,918 m Converse County, Wyoming

TYPE OF OPERATION: Coal-Fired Electric Generating Plant

RESPONSIBLE OFFICIAL: Gary Slanina, Managing Director

MAILING ADDRESS: 1591 Tank Farm Road Glenrock, WY 82637

TELEPHONE NUMBER: (307) 436-2001

REVIEWERS: Cole Anderson, Air Quality Engineer Josh Nall, Air Quality Modeler

PURPOSE OF APPLICATION:

Sections 169A and 169B of the 1990 Clean Air Act Amendments require states to improve visibility at Class I areas. On July 1, 1999, EPA first published the Regional Haze Rule, which provided specific details regarding the overall program requirements to improve visibility. The goal of the regi onal haze program is to achieve natural conditions by 2064.

Section 308 of the Regional Haze Rule (40 CFR part 51) includes discussion on control strategies for improving visibility impairment. One of these strategies is the requirement under 40 CFR 51.308(e) for certain stationary sources to install Best Available Retrofit Technology (BART) to redu ce emissions of three (3) visibility impairing pollutants, nitrogen oxides (NO

x ), particulate matter (PM), and sulfur dioxide (SO 2 ). EPA published Appendix Y to part 51 - Guidelines for BART Determinations Under the Regional Haze Rule in the July 6, 2005 Federal Register to provide guidance to regulatory authorities for making BART determinations. Chapter 6, Section 9, Best Available Retrofit Technology was adopted into the Wyoming Air Quality Standards and Regulations (WAQSR) and became effective on December 5, 2006. The Wyoming Department of Environmental Quality, Air Quality Division (Division ) will
determine BART for NO

x and PM 10 for each source subject to BART and include each determination in the §308 Wyoming Regional Haze State Implementation Plan (SIP).PacifiCorp Dave Johnston Plant

AP-6041 BART Application Analysis Page 22

Table 16: Dave Johnston Unit 3 Economic Costs

Cost Existing
Combustion
Control Dry FGD

with ESP Dry FGD with

ESP and Polishing
Fabric Filter Wet FGD

with ESP Control Equipment Capital

Cost $0 $91,499,734 $169,500,000 $144,300,464

Capital Recovery Factor N/A 0.09513 0.09513 0.0951 3

Annual Capital Recovery

Costs $0 $8,704,370 $16,124,535 $13,727,303

Annual O&M Costs $0 $4,455,188 $5,295,598 $6,044,908

Annual Cost of Control $0 $13,159,558 $21,420,133 $19,772,211

Table 17: Dave Johnston Unit 3 Environmental Costs

Existing
Combustion
Control Dry FGD

with ESP Dry FGD with

ESP and Polishing
Fabric Filter Wet FGD

with ESP

SO 2 Emission Rate (lb/MMBtu) 1.2 0.22 0.15 0.06

Annual SO 2 Emission (tpy) (a) 13,316 2,428 1,656 662

Annual SO 2 Reduction (tpy) N/A 10,888 11,660 12 ,654

Annual Cost of Control $0 $13,159,558 $21,420,133 $19,772,211

Cost per ton of Reduction N/A $1,209 $1,837 $1,563

Incremental Cost per ton of
Reduction N/A $1,209 $10,700 -$1,658 (b)

(a) Annual emissions based on unit heat input rate of 2,800 MMBtu/hr and 7,884 hours of operation per year.
(b) Incremental cost from dry FGD with ESP and fabric filter is negative as a result of the lower annual cost of control for wet
FGD with ESP.

Table 18: Dave Johnston Unit 4 Economic Costs

Cost Existing
Combustion
Control Dry FGD with

Full -scale
Fabric Filter Wet FGD with

Full -scale
Fabric Filter

Control Equipment Capital Cost $0 $243,100,000 $289,166,335

Capital Recovery Factor N/A 0.09513 0.09513

Annual Capital Recovery Costs $0 $23,126,103 $27,508,393

Annual O&M Costs $0 $5,318,117 $6,961,183

Annual Cost of Control $0 $28,444,220 $34,469,576PacifiCorp Dave Johnston Plant

AP-6041 BART Application Analysis Page 23

Table 19: Dave Johnston Unit 4 Environmental Costs Existing
Combustion
Control Dry FGD with

Full -scale
Fabric Filter Wet FGD with

Full -scale
Fabric Filter

SO 2 Emission Rate (lb/MMBtu) 0.5 (a) 0.15 0.10

Annual SO 2 Emission (tpy) (b) 8,081 2,424 1,616

Annual SO 2 Reduction (tpy) 0 5,657 6,465

Annual Cost of Control $0 $28,444,220 $34,469,576

Cost per ton of Reduction N/A $5,028 $5,332

Incremental Cost per ton of
Reduction N/A $5,028 $7,457

(a) 30-day rolling average SO 2 limit from Operating Permit 31-148-1 used as baseline.
(b) Annual emissions based on unit heat input rate of 4,100 MMBtu/hr and 7,884 hours of operation per year.

The cost effectiveness and incremental cost effectiveness of the proposed wet FGD and dry FGD controls for Units 3 and 4 are reasonable, except for the incremental cost effectiveness of installing a new polishing fabric filter with dry FGD on Unit 3. The final step in the SO 2 BART determination process for Dave Johnston Units 3 and 4, Step 5: Evaluate visibility impacts, is addressed in a comprehensive visibility analysis presented in the next section of this BART application analysis. T he Division evaluated the amount of visibility improvement gained from the application of additional NO

x , PM/PM 10 , and SO 2 emission control technology in relation to all three visibility impairing pollut ants. Table 23 on page 34 and Table 24 on page 35 list the modeled control scenarios and associated emission rates.

VISIBILITY IMPROVEMENT DETERMINATION:

The fifth of five steps in a BART determination analysis, as required by 40 CFR part 51 Appendix Y , is the determination of the degree of Class I area visibility improvement that would r esult from installation of the various options for control technology. This factor was evaluated for the Pa cifiCorp Dave Johnston plant with an EPA-approved dispersion modeling system (CALPUFF) to predict the changes in Class I area visibility. The Division had previously determined that the facility was subje ct to BART based on the results of initial screening modeling using current (baseline) emissions from the f acility. The screening modeling, as well as more refined modeling conducted by the applicant, is described in detail
below.

Wind Cave and Badlands National Parks (NP) in South Dakota are Class I areas located to the northeast of the plant at a distance of approximately 200 kilometers (km) and 290 km, respectively. Toward the south in Colorado, Rawah Wilderness Area (WA) and Mount Zirkel WA are both located approximately 220 km from the plant, with Rocky Mountain NP located beyond Rawah WA.